Table Of Contents
MPLS Traffic Engineering (TE)—Automatic Bandwidth Adjustment for TE Tunnels
Related Features and Technologies
Supported Standards, MIBs, and RFCs
Configuring a Platform to Support Traffic Engineering Tunnels
Configuring IS-IS for MPLS Traffic Engineering
Configuring OSPF for MPLS Traffic Engineering
Configuring an MPLS Traffic Engineering Tunnel
Configuring Bandwidth on Each Link That the Tunnels Cross
Configuring a Platform to Support Automatic Bandwidth Adjustment
Configuring Automatic Bandwidth Adjustment for a Tunnel
Configuring the Interval for Computing Tunnel Average Output Rate
MPLS Traffic Engineering Configuration for Automatic Bandwidth
Tunnel Configuration for Automatic Bandwidth
clear mpls traffic-eng auto-bw timers
mpls traffic-eng auto-bw timers
tunnel mpls traffic-eng auto-bw
MPLS Traffic Engineering (TE)—Automatic Bandwidth Adjustment for TE Tunnels
This feature module describes Multiprotocol Label Switching (MPLS) automatic bandwidth adjustment for Release 12.0(14)ST. Automatic bandwidth adjustment is a feature of traffic engineering.
This document contains the following sections:
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Supported Standards, MIBs, and RFCs
Feature Overview
Traffic engineering automatic bandwidth adjustment provides the means to automatically adjust the bandwidth allocation for traffic engineering tunnels based on their measured traffic load.
Traffic engineering autobandwidth samples the average output rate for each tunnel marked for automatic bandwidth adjustment. For each marked tunnel, it periodically (for example, once per day) adjusts the tunnel's allocated bandwidth to be the largest sample for the tunnel since the last adjustment.
The frequency with which tunnel bandwidth is adjusted and the allowable range of adjustments is configurable on a per-tunnel basis. In addition, the sampling interval and the interval over which to average tunnel traffic to obtain the average output rate is user-configurable on a per-tunnel basis.
Benefits
The automatic bandwidth feature makes it easy to configure and monitor the bandwidth for MPLS traffic engineering tunnels. If automatic bandwidth is configured for a tunnel, traffic engineering automatically adjusts the the tunnel's bandwidth.
Restrictions
The automatic bandwidth adjustment feature treats each tunnel for which it has been enabled independently. That is, it adjusts the bandwidth for each such tunnel according to the adjustment frequency configured for the tunnel and the sampled output rate for the tunnel since the last adjustment without regard for any adjustments previously made or pending for other tunnels.
Related Features and Technologies
The automatic bandwidth feature is related to the following:
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Related Documents
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Supported Platforms
Automatic bandwidth is supported on the following platforms:
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Supported Standards, MIBs, and RFCs
Standards
This feature does not support any new or modified standards.
MIBs
This feature supports the MPLS Traffic Engineering MIB.
To obtain lists of MIBs supported by platform and Cisco IOS release and to download MIB modules, go to the Cisco MIB web site on Cisco Connection Online (CCO) at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
This feature does not support any new or modified RFCs.
Prerequisites
Your network must support the following:
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Configuration Tasks
Perform the following tasks before you enable automatic bandwidth adjustment:
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Perform the following tasks to configure automatic bandwidth adjustment:
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Configuring a Platform to Support Traffic Engineering Tunnels
To configure a platform to support traffic engineering tunnels, perform the following steps in configuration mode:
Configuring IS-IS for MPLS Traffic Engineering
To configure IS-IS for MPLS traffic engineering, perform the steps described below. For a description of the IS-IS commands, see the Cisco IOS Network Protocols Command Reference, Part 1, and the MPLS Traffic Engineering and Enhancements manual.
Configuring OSPF for MPLS Traffic Engineering
To configure OSPF for MPLS traffic engineering, perform the steps described below. For a description of the OSPF commands, see the Cisco IOS Network Protocols Command Reference, Part 1, and the MPLS Traffic Engineering and Enhancements manual.
Configuring an MPLS Traffic Engineering Tunnel
To configure an MPLS traffic engineering tunnel, perform these steps in interface configuration mode. This tunnel has two path setup options: a preferred explicit path and a backup dynamic path. For more detailed descriptions of the commands and their arguments, see the MPLS Traffic Engineering and Enhancements manual.
Configuring Bandwidth on Each Link That the Tunnels Cross
To configure bandwidth on each link that the tunnels cross, perform the following steps:
Configuring a Platform to Support Automatic Bandwidth Adjustment
To enable automatic bandwidth adjustment on a platform and initiate sampling the output rate for tunnels configured for bandwidth adjustment, enter the following global configuration command:
To disable automatic bandwidth adjustment on a platform, use the no version of the command; that terminates output rate sampling and bandwidth adjustment for tunnels. In addition, the no form of the command restores the configured bandwidth for each tunnel where "configured bandwidth" is determined as follows:
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Configuring Automatic Bandwidth Adjustment for a Tunnel
To enable automatic bandwidth adjustment for a tunnel and constrain the range of automatic bandwidth adjustments applied to the tunnel, perform these steps in interface configuration mode:
Configuring the Interval for Computing Tunnel Average Output Rate
To specify the interval for computing the average output rate for an MPLS traffic engineering tunnel, use the load-interval command shown below.
Verifying the Configuration
To verify that automatic bandwidth has been configured, enter the command shown below. For a detailed description of the command, see the MPLS Traffic Engineering and Enhancements manual.
Router(config)# show mpls traffic-eng tunnels tunnel_interfaceShows information about tunnels, including automatic bandwidth information for tunnels that have the feature enabled.
Example:
The following is sample output from the show mpls traffic-eng tunnels command. In the command output
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Router-1# show mpls traffic-eng tunnels
Name:tagsw4500-9_t1 (Tunnel1) Destination:10.0.0.11Status:Admin:up Oper:up Path:valid Signalling:connectedpath option 1, type explicit pbr_south (Basis for Setup, path weight 30)path option 2, type dynamicConfig Parameters:Bandwidth:5000 kbps (Global) Priority:7 7 Affinity:0x0/0xFFFFAutoRoute: disabled LockDown:disabled Loadshare:5000 bw-basedauto-bw:(86400/85477) 5347 Bandwidth Requested:5000Troubleshooting Tips
Each tunnel mpls traffic-eng auto-bw command supersedes the previous one. Therefore, if you want to specify multiple options for a tunnel, you must specify them all in a single tunnel mpls traffic-eng auto-bw command.
Configuration Examples
This section provides the following configuration examples:
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Figure 1 illustrates a sample MPLS topology. The next sections contain sample configuration commands to configure automatic bandwidth adjustment for MPLS traffic engineering tunnels originating on Router 1 and to enable it for Tunnel1. The examples omit some configuration required for MPLS traffic engineering, such as the required RSVP and IGP (IS-IS or OSPF) configuration, because the purpose of these examples is to illustrate the configuration for automatic bandwidth adjustment. For information about configuring MPLS traffic engineering see the MPLS Traffic Engineering and Enhancements manual.
Figure 1 Sample MPLS Traffic Engineering Tunnel Configuration
MPLS Traffic Engineering Configuration for Automatic Bandwidth
The following illustrates how to use the mpls traffic-eng auto-bw timers command to enable automatic bandwidth adjustment for Router 1. The command specifies that the output rate is to be sampled every 10 minutes for tunnels configured for automatic bandwidth.
ip cefmpls traffic-eng tunnelsmpls traffic-eng auto-bw timers frequency 600 !Enable automatic bandwidth adjustmentinterface loopback 0ip address 11.11.11.11 255.255.255.255Tunnel Configuration for Automatic Bandwidth
The following example illustrates how to use the tunnel mpls traffic-eng auto-bw command to enable automatic bandwidth adjustment for Tunnel1. The command specifies a maximum allowable bandwidth of 2000 kbps, a minimum allowable bandwidth of 1000 kbps, and that the default automatic bandwidth adjustment frequency of once a day be used.
interface tunnel1ip unnumbered loopback 0tunnel destination 17.17.17.17tunnel mode mpls traffic-engtunnel mpls traffic-eng bandwidth 1500tunnel mpls traffic-eng priority 1 1tunnel mpls traffic-eng path-option 1 dynamictunnel mpls traffic-eng auto bw max-bw 2000 min-bw 1000 !Enable automatic bandwidth!adjustment for Tunnel1Command Reference
This section documents the following new or modified commands:
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All other commands used with this feature are documented in the Cisco IOS Release 12.0 and Release 12.1 command reference publications.
clear mpls traffic-eng auto-bw timers
To reinitialize the automatic bandwidth adjustment feature on a platform , use the clear mpls traffic-eng auto-bw timers EXEC command.
clear mpls traffic-eng auto-bw timers
Syntax Description
This command has no arguments or keywords.
Defaults
None.
Command Modes
EXEC
Command History
Usage Guidelines
For each tunnel for which automatic bandwidth adjustment is enabled, the platform maintains information about sampled output rates and the time remaining until the next bandwidth adjustment. The clear mpls traffic-eng auto-bw timers command clears this information for all such tunnels. The effect is as if automatic bandwidth adjustment had just been enabled for the tunnels.
Examples
The following command clears information about sampled output rates and the time remaining until the next bandwidth adjustment:
Router# mpls clear traffic-eng auto-bw timersClear traffic engineering auto-bw timers [confirm]Router#Related Commands
mpls traffic-eng auto-bw timers
To enable automatic bandwidth adjustment for a platform and to start output rate sampling for tunnels configured for automatic bandwidth adjustment, use the mpls traffic-eng auto-bw timers global configuration command. To disable automatic bandwidth adjustment for the platform, use the no form of this command.
mpls traffic-eng auto-bw timers [frequency sec]
no mpls traffic-eng auto-bw timers
Syntax Description
frequency sec
(Optional) Interval, in seconds, for sampling the output rate of each tunnel configured for automatic bandwidth. The value must be from 1 through 604800. The recommended value is 300.
Defaults
When the frequency optional parameter is not specified, the sampling interval is 300 seconds (5 minutes).
Command Modes
Global configuration
Command History
Usage Guidelines
The mpls traffic-eng auto-bw timers command enables automatic bandwidth adjustment on a platform by causing traffic engineering to periodically sample the output rate for each tunnel configured for bandwidth adjustment.
The no mpls traffic-eng auto-bw timers command disables automatic bandwidth adjustment for a platform by terminating the output rate sampling and bandwidth adjustment for tunnels configured for adjustment. In addition, the no form of the command restores the configured bandwidth for each tunnel where "configured bandwidth" is determined as follows:
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Examples
The following example designates that for each MPLS traffic engineering tunnel, the output rate is sampled once every 10 minutes (every 600 seconds):
Router(config)# mpls traffic-eng auto-bw timers frequency 600Related Commands
tunnel mpls traffic-eng auto-bw
To configure a tunnel for automatic bandwidth adjustment and to control the manner in which the bandwidth for a tunnel is adjusted, use the tunnel mpls traffic-eng auto-bw interface configuration command. To disable automatic bandwidth adjustment for a tunnel, use the no version of this command.
tunnel mpls traffic-eng auto-bw [collect-bw] [frequency sec] [max-bw n][min-bw n]
no tunnel mpls traffic-eng auto-bw
Syntax Description
Defaults
If the command is entered with no optional parameters, automatic bandwidth adjustment for the tunnel is enabled, with adjustments made every 24 hours and with no constraints on the bandwidth adjustments made.
If the collect-bw option is entered, the tunnel's bandwidth is sampled but not adjusted, and the other options, if any, are ignored.
If the collect-bw option is not entered and some, but not all of the other options are entered, the defaults for the options not entered are: frequency, every 24 hours; min-bw, unconstrained (0); max-bw, unconstrained.
Command Modes
Interface configuration
Command History
Usage Guidelines
To sample the bandwidth used by a tunnel without automatically adjusting it, specify the collect-bw argument in the tunnel mpls traffic-eng auto-bw command.
If you enter the tunnel mpls traffic-eng auto-bw command without the collect-bw option, the tunnel's bandwidth is adjusted to the largest average output rate sampled for the tunnel since the last bandwidth adjustment for the tunnel was made.
To constrain the bandwidth adjustment that can be made to a tunnel, use the max-bw and/or min-bw arguments and specify the permitted maximum allowable bandwidth and/or minimum allowable bandwidth, respectively.
The no form of the tunnel mpls traffic-eng auto-bw command disables bandwidth adjustment for the tunnel and restores the configured bandwidth for the tunnel bandwidth where "configured bandwidth" is determined as follows:
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Examples
The following commands enable automatic bandwidth adjustment for tunnel102 and specify that the adjustments are to occur every hour:
Router(config)# interface tunnel102Router(config-if)# tunnel mpls traffic-eng auto-bw frequency 3600Related Commands
Enables automatic bandwidth adjustment on a platform for tunnels configured for bandwidth adjustment.
Guest
